/* utf.js - UTF-8 <=> UTF-16 convertion
*
* Copyright (C) 1999 Masanao Izumo <iz@onicos.co.jp> & 2006 Ma Bingyao <andot@ujn.edu.cn>
* Version: 1.1
* LastModified: Feb 17 2006
* This library is free. You can redistribute it and/or modify it.
*/
/*
* Interfaces:
* utf8 = utf16to8(utf16);
* utf16 = utf16to8(utf8);
*/
function utf16to8(str) {
var out, i, len, c;
out = [];
len = str.length;
for(i = 0; i < len; i++) {
c = str.charCodeAt(i);
if ((c >= 0x0001) && (c <= 0x007F)) {
out[i] = str.charAt(i);
} else if (c > 0x07FF) {
out[i] = String.fromCharCode(0xE0 | ((c >> 12) & 0x0F),
0x80 | ((c >> 6) & 0x3F),
0x80 | ((c >> 0) & 0x3F));
} else {
out[i] = String.fromCharCode(0xC0 | ((c >> 6) & 0x1F),
0x80 | ((c >> 0) & 0x3F));
}
}
return out.join('');
}
function utf8to16(str) {
var out, i, len, c;
var char2, char3;
out = [];
len = str.length;
i = 0;
while(i < len) {
c = str.charCodeAt(i++);
switch(c >> 4)
{
case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
// 0xxxxxxx
out[out.length] = str.charAt(i-1);
break;
case 12: case 13:
// 110x xxxx 10xx xxxx
char2 = str.charCodeAt(i++);
out[out.length] = String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
break;
case 14:
// 1110 xxxx 10xx xxxx 10xx xxxx
char2 = str.charCodeAt(i++);
char3 = str.charCodeAt(i++);
out[out.length] = String.fromCharCode(((c & 0x0F) << 12) |
((char2 & 0x3F) << 6) | ((char3 & 0x3F) << 0));
break;
}
}
return out.join('');
}